NOTES AND MEMORANDA. 285 



sacral and carotidean glands, the coi'idus luteum, and pituitary body. 

 Fifthly, the connective tissue of the testis consists of various-sized 

 trabeculae of connective tissue, which form a network, and are covered 

 by an endothelial layer of cells, which last is continued from them on 

 to the seminal tubules and blood-vessels. Sixthly, the lymphatics 

 commence in the inters2)aces of the fasciculi of connective tissue 

 invested by endothelium, and partly in the lacunae of the lamella of 

 the walls of the seminal tubules. No true tubular lymphatics with 

 defined walls exist in the testis at all. Lastly, the tubuli seminiferi 

 are closely surrounded by a layer of capillary blood-vessels, intimately 

 connected with the membrana j^rojn-ia. 



NOTES AND MEMOEANDA. 



Cell-culture in the Study of Fungi. — Ph. Van Tieghem and 

 G. LeMonnier in their published researches on the Mucorini give 

 a good working account of their method of cell-culture which is 

 applicable not only to the smaller fungi but to many other plants. 

 I'he method is as follows, according to the 'American Naturalist,' 

 Nov., 1874 : — A glass cell i or ^ inch is cemented upon a glass 

 slide, and a suitable cover glass is kejjt in place by three minute drops 

 of oil placed on the edge of the ring. The contained air is kept moist 

 by a few drops of water placed in the bottom of the cell, while a very 

 small drop of the nutritive fluid is placed on the lower surface of the 

 cover glass, and in this drop the sj^ore to be cultivated is sown. The 

 whole drop, and indeed the entire contents of the cell, can now be 

 examined with suitable powers, and the germination and development 

 of the plant traced hour after hour from any given sjjore, with the 

 greatest certainty and ease. Extraneous spores will sometimes be 

 introduced, but they are easily detected. 



American Opinion on Angular Apertures. — An anonymous writer 

 in the last number of the ' American Naturalist ' makes the following 

 remarks on this subject : — " It is not yet forgotten that at the London 

 examination of the ^-inch lens sent to demonstrate the possibility of 

 obtaining an excessive angular aperture in immersion work on balsam 

 objects, the lens was measured at an adjustment of which nothing to 

 the point was known except that it was not a position of immersion 

 work at all, nor a recognized maximum position for any kind of work ; 

 the plain fact being that the accomplished committee were so bent 

 upon teaching ns the familiar fact of reduced angle that they seem to 

 have forgotten to look for any other possibility in the case. Nor is it 

 likely to be forgotten as long as Mr. Wenham so far forgets his usual 

 and admirable caution as to allude to the correction of this pal23able 

 mistake as an ' after quibble,' nor while the eminent President of the 

 Royal Microscopical Society utters in his formal Address such an 



